The present disclosure relates generally to apparatus for medical imaging. More particularly, embodiments of the present disclosure relate to mobile apparatus for medical imaging. As described herein, “mobile” is intended to describe apparatus for medical imaging which is movable between different locations in a medical facility. Embodiments of the present disclosure relate particularly to mobile apparatus for fluoroscopic medical imaging having a C-arm, O-arm, L-arm or other imaging assembly. Particularly, embodiments of the disclosure relate to mobile apparatus for medical imaging which includes a C-arm imaging assembly. Hereinafter such apparatus is referred to as a “mobile C-arm imaging system”. As described herein, a mobile C-arm imaging system includes an imager suitable for generating an image of a subject, such as a human subject. In one common application, the imager includes an X-ray tube for generating X-rays to image the subject. A mobile C-arm imaging system includes a C-arm assembly which supports the imager, such as an X-ray tube, in a desired position relative to the subject to be imaged. A mobile C-arm imaging system also includes a base assembly which supports the C-arm assembly. The base assembly has a set of wheels for transporting the mobile C-arm imaging system between locations and for maneuvering the system into desired stationary positions at each location.
Mobile C-arm imaging systems are used in a variety of clinical environments, such as hospital radiology and surgery departments. As described above, the C-arm assembly typically supports an imager such as an X-ray tube in a desired position relative to the subject. In some configurations, the C-arm assembly remains stationary relative to the subject for single angle imaging. In other configurations, the C-arm assembly moves relative to the subject in order to acquire images from multiple angles. In some arrangements, the C-arm assembly is manually repositioned to generate images from different angles. In other arrangements, the C-arm assembly is moved along a predetermined path by operation of a motorized drive mechanism in order to generate images from multiple angles. Mobile C-arm imaging systems including motorized drive mechanisms for moving the C-arm assembly generally are larger and heavier than manual arrangements. Mobile C-arm imaging systems including larger, heavier, and more powerful X-ray tubes generally are larger and heavier than systems using smaller X-ray tubes.
Mobile C-arm imaging systems typically include a set of wheels for rolling the system across floors between different stationary imaging locations within a facility. Overall length and overall size of the system can limit the paths along which the system can be transported. For example, small passages such as elevators and confined corners can prevent systems from being rolled into various locations within a facility. Overall length and overall size can also limit locations which will accommodate the system in a stationary position for imaging. For example, use of a mobile C-arm imaging system in some operating rooms may be prevented or limited by overall length or overall size of the system. Also, operating rooms frequently are crowded with various equipment and personnel, and the overall length and size of a mobile C-arm imaging system can interfere with personnel and activities in the immediate vicinity of the operating table. The length of the C-arm assembly and the overall length of the system can limit the maneuverability of the system within a facility. Referring again to the operating room environment, and referring particularly to the crowded immediate vicinity around an operating table, maneuverability of the system relative to the operating table and the human subject can be limited by the length of the C-arm assembly and overall length of the system. Mobile C-arm imaging systems can pose a tipping hazard, in part because the length and mass of the C-arm assembly negatively influences the center of gravity. Typically, the hazard of tipping is increased when a mobile C-arm imaging system is rolled across an incline during transport. Lateral swinging of the C-arm assembly can damage the C-arm assembly, personnel or material impacted by the C-arm assembly.
The C-arm assembly can support several hundred kilograms of mass in an elevated position, and the C-arm assembly can be repositioned or rotated between imaging scans. A mobile C-arm imaging system includes a body which serves as a counterweight to the elevated mass of the C-arm. Adding a unit of mass to the distal end of the C-arm assembly requires an increase of several units of mass in the overall weight of the system. Such a weight increase is necessary in order to increase the mass of the base assembly and counterbalance the increased, elevated mass of the C-arm assembly. Mobile C-arm imaging systems having heavier C-arms and base assembly bodies generally are larger and consequently require more space than lighter systems. Increased system mass and size reduce positioning flexibility around the surgical table, reduce maneuverability for transporting the mobile C-arm system between imaging locations within a facility, increase the amount of material necessary to manufacture each system, and increase the cost of shipping systems.